It is well know to professionals skilled in the art of healing, that a wound at any part of the human body can be provoked either by a pathological agent, as well through a traumatic agent. In either cases, the final result is a wound which segregates fluids, accumulates detritus and creates a bacteria breeding site, which in direct function of the nature and size of the wound, may impede its healing. On the other hand, a fistula is an orifice open from within an organ or limb in the human body, with an outlet.
A healing process implies cleansing the wound, drying same of noxious fluids, and since a wound may be considered as an infectious cavity within the body, a fistula is a wound defining a passage or opening communicating one of more internal organs with the outer environment. The healing process for these medical pathologies are successful when the wound is clean and dry, ceasing in its emission of humorous fluids and detritus. Most of these are provoked by the activity of bacteria and pathogenic agents, which according to their nature must have a sufficient threshold of oxygen pressure in order to live and multiply, or in the case of gangrene, the absence of oxygen is required for same to infest the body.
The necessary oxygen pressure for these bacteria, or the like, to thrive is attained at sea level at atmospheric pressure (760 mm Hg.), and in the case of gangrenes it has been found that a reasonable acceptable means of oxygenating the base of the gangrenous wound is to induce an increase of blood irrigation in its area. As a rule an infected wound produces an interface between the external environment and the base of the wound. It is also known that atmospheric air at a pressure of 760 mm Hg. has an average of 20% in oxygen. This means the oxygen present in air is responsible for 150 mm Hg. as measured in the pressure column. It is further common knowledge that any living organism needs an average column of 100 mm Hg. in oxygen in order to allow the oxygen exchange through its cell membrane, while under this oxygen pressure it is not possible to sustain life due to lack of the vital oxygen exchange.
In the following exposition, it will be only be made mention to a fistula in the abdominal region, which has interested a portion of intestine, short-circuiting the digestive tract, without this sole mention being capable to construe any limitation to the actual scope of this instant invention, which can be applied to any wound as above said, and specifically to fistulas in any part of the body, being this scope delimited by the first claim of this patent.
As known to the skilled in the art, a fistula implies some serious inconveniences, such as:
undernourishment, if said fistula is an intestinal fistula, with an elevated flow of humorous fluids; PA1 loss of body fluids and electrolytes (such as blood, etc.) PA1 a degradation process of the tissue in the area surrounding said fistula, since the body humours exiting from said wound acts as a ferment. PA1 medical treatment, or PA1 chirurgic treatment. PA1 placing, over the zone of the patient afflicted with the pathology (for instance the orifice of the fistula and in all the volume of the wound thus delimited), a mass of polymeric flock , preferably of crimped fibers with a diameter from 0.0005 mm to 1 mm, and with a length in between 3 cms up to 50 cms, forming these fibers a bundle or a non-woven of flock, or a web with a web value of 05, to 6 deniers, forming an obturation plug in said fistula or a rigid layer against the bone fracture, and substantially at a level with the skin of the patient; PA1 then placing over the zone with the pathology to be treated, and covering entirely same, a self adhesive polymeric material laminar sheet, made out of a low deformability, waterproof, two-axis oriented polyolefinic polymer, with a thickness between 10 to 30 microns, being this laminar sheet adhered against the skin of the patient by means of a known adhesive; creating a compacting airtight chamber over said area with the pathology to be treated, covering the skin of the patient over said area and covering said mass of flock as well, this laminar sheet can be of the self-adhesive kind; PA1 this laminar sheet is perforated by the end of an aspiration tube with is introduced into said mass of fibers, establishing an airtight relationship between said tube and said laminar sheet at said perforation; PA1 closing said first flow valve and producing the vacuum by activating the vacuum pump extracting the air contained within said chamber, sending same into said vessel, maintaining the activity of the vacuum pump until a negative pressure around -700 mmHg is attained, and with an air extraction flow rate of 100 to 300 litters/minute; once the programmed depression is attained, the vacuum pump is detained, either cutting of its power source or acting over the second flow valve or a shut-off valve; PA1 keeping a stabilized depression in the vessel, the first flow valve is opened, producing the instant compactness of the mass of fibers; PA1 a stabilized depression is maintained at reasonable constant values between said compacting chamber and said vessel, with the vacuum pump shut off, while said compactness of the mass of fibers is maintained at a value between 80 to 95% of the original value, forming a compacted mass due to the action of the vacuum, and a positive pressure over the abdominal walls compensating the pressures within the body of the patient; PA1 at the necessary intervals of time, the first flow valve is closed, keeping the values of the vacuum in the airtight chamber, and opening the second flow valve producing the draining of the vessel's contents, then closing said second flow valve and opening one more the first flow valve; PA1 repeat these operations all the necessary time required until the healing process has been completed.
This means a fistula acts, like a true communication opening through which, (as in this chosen non limiting example) one or more portions of intestine are thus in direct communication with the external environment, short-circuiting the lower digestive tract.
Considering always the abdominal fistulas, it is believed post-chirurgic entero-cutaneous fistulas appears between 0.5 to 2% of all patients with abdominal operations. Depending on the treated pathology, and also considering if we are dealing with emergency surgery or programmed interventions, when and if a fistula papers, it aggravates the prognosis for the patient. The flow rate of the intestinal contents, its proteolitic activity, its anatomical placing, the peritoneal infection, the difficulty in the distal transit and the base illness, are causes whose combination averages a mortality rate between 20 to 40% of all patients thus affected.
Professionals skilled in the art knows that when a fistulae appears, they have two choices:
As a rule, considering the inherent complications attached to a chirurgic treatment of fistulas, there is a tendency to try to obtain its obturation through medical treatment.
Chirurgy is not always practicable since the orifices segregates a high flow rate of intestinal liquids (an average of 1500 cc/ day), and the aggression of these liquids at its full final digestive process literally "digests" or "eats" the new tissue intended to precisely close the orifice. There exists an important relative pressure within the intestine, which pumps the liquids in a natural way towards the end of the digestive tract, helping same to exit with any contention through said fistula. In the operated cases the recidivate reaches around 20%.
Of the several procedures tried out in the past for the closing of fistula openings, no one gave the expected mortality reductions rate results.
Beginning by surgery, it has been already explained why same cannot prosper. It is known to have been tried to obturate the orifices with adhesives, including instant adhesivation, but it was not possible to maintain dry the wound area.
In order to reduce a secretion rate, traditionally it has been used a continues aspiration, applied to the wound, along with the prescription of antiexocrine medication, and this forces the patient to lay in bed, tending to create the necessary conditions for a pulmonary emboli, pulmonary hipostasia with risks of pulmonary infection.
It is also necessary to replace intravenously into the patient the lost electrolytes due to the secretion flow rate, and a long term parental feeding which produces a high mortality rate of due to these causes.
The last consideration given to fistulas treated with the known traditional methods is time: in effect, it has been known cases in which the patent has been subjected to post-surgery terms of several months, sometimes even almost an year, with being able to walk, and acute nutritional problems.